Octadecane(OtBu)-Glu(ɑ-OtBu)-AEEA-AEEA-OH is a intermediate for semaglutide fragment chemical synthesis. It also react witn Arg34GLP-1(9-37)、Arg34GLP-1 (10-37) and Arg34GLP-1(11-37) (precursors from Gene recombination fermentation) respectly to obtain semaglutide.